Sometimes you think your shock absorbers are fine but the tyre shop tells you otherwise. They say they need replacing. Are they telling you the truth? How do you even tell that your shocks need to be replaced? You've never really paid attention to your shock absorbers and that's normal for the majority of car owners.
When purchasing a used/recon car, it is common to get a car with bad/shot/leaking shock absorbers. If they’re not yet broken, they usually are the moment you pay the money. If you have a beater car, bad shocks are usually neglected since the car isn’t driven as hard anyway. However, for safe daily driving, we wouldn’t recommend using bad shocks.
Shock absorbers, as the name suggests, absorb shock. They do not affect the car’s ride height. Without shock absorbers (only springs), your car will be bouncing around all day long.
We may have used the term shocks and struts interchangeably but they are different things. A strut is an assembly that consists of a shock in the middle surrounded by a spring. A shock is just a shock. Most commonly found in cars these days is the MacPherson Strut.
Besides being crucial for handling, shock absorbers also play a big part in braking. They are very important for safety.
With that in mind, it is important that you keep your shock absorbers in check.
Let’s go through a few signs that your shock absorbers are in bad shape and need to be replaced.
1. Excessive Nose Diving & Squatting
Braking and accelerating shifts the weight of the car. Braking shifts the weight to the front, while accelerating shifts the weight to the back. Bad shock absorbers cause excessive “diving” or "squatting" when you brake or accelerate.
Excessive nose diving means the car’s rear end becomes light, rendering the rear brakes and tyres useless in the event of emergency braking.
Bad shock absorbers increase your braking distance and increase your risk of collision. Bad stuff.
Besides excessive nose diving, excessive squatting is also a sign of bad shocks. With the weight transferred to the rear, bad shocks are unable to dampen the weight shift well.
2. Excessive Body Roll
Like nose diving and squatting, body roll is just another part of vehicle dynamics. Look at the picture below to grasp what body roll is. The body rolls. That’s it.
Excessive body roll could cause you to loose control of your car, and is definitely not good for the Moose Test. An alternative for the Moose test is probably the Fujiwara water-in-a-cup test.
3. Leaking Shocks
Shock absorbers are hydraulic. It means they contain fluid. Overtime, the seals may wear out and cause leaking of the hydraulic fluid. Slight misting is still tolerable for absorber health. This picture from CARiD is a good representation of the health of your shock absorbers and when you should replace them.
4. Excessive bouncing
Pressing the car is not a very accurate way to test the health of your shocks. Unless they’re really bad, it is really hard to tell by just pressing the car. A better way is to drive the car over a bump and see how long the car remains bouncing.
A good shock absorber will not make the car bounce excessively. A bad shock absorber will make the car bounce ‘til kingdom come
5. Shaking Steering Wheel
Drive through a bumpy road and observe if the steering wheel shakes. A shaking steering wheel when driving through rough roads is a sign of bad shocks.
6. Cupped tyres
Bad shock absorber will cause uneven wear of the tyre thread. More specifically it, will cause “cupping” wear as shown in the picture below. If you see this, both your shocks and your tyres need replacing.
So, there you have it - 6 signs you need to get your shock absorbers/struts replaced. Although usually neglected, shock absorbers play a big role in keeping your car safe for yourself and other road users as well. Keep your car in check and drive safe.